Apparatus for casting cast-iron pipes



May 18, 1926. 1,585,391

G. KUBOTA APPARATUS FOR CASTING CAST IRON PIPES Filed Dec, 13, 1932 Ha I HQ II 5| nuantoz 1 Ww Z Patented May 18, 1926.

UNITED STATES GONSI-IIRO KUBOTA, OF MINAMI-KU, OSAKA, JAPAN.

APPARATUS FOR CASTING CAST-IRON PIPES.

Application filed December 13, 1922. Serial No. 606,588.

This invention relates to improvements in apparatus for casting iron pipes, the object of the invention being to provide a metallic mold for this purpose, in which provision is made for longitudinal expansion of the mold, the construction of which is such that the heatof the molten metal is not absorbed and any deformations of the mold due to the high temperature to which it is subjected can be readily corrected.

With the foregoing and other objects in view, which will appear as the description proceeds, the invention consists in the novel features of construction and combination of parts which willbe more fully described hereinafter and particularly pointed outin the claim.

In the drawings accompanying and forum ing part of this specification Fig. 1 is a partly sectional side elevation of the assembled mold;

Fig. 2 is a side view of the upper part of the mold illustrating a form of means for suspending said mold;

Fig. 3 is a perspective view of a portion of the mold showing a detail of construction; and

Fig. 4 is a sectional plan view taken on the line IVIV of Fig. 1.

The same characters of reference designate the same parts in the different figures of the drawings.

It is well known that molds heretofore used for casting elongated objects, such as iron pipes, were made of sand. So far as I am aware, metallic molds have never been used for this purpose, for the reason that the mold would quickly absorb the heat of the molten metal that was poured into it and thus chill the surface of the cast pipe and make it rough. Furthermore, the expansion and contraction of the metallic molds did not coincide with those of the congealing metal poured into the molds. and consequently the pipe cast in the mold was apt to crack while cooling down. Moreover, metallic molds easily become deformed owing to the excessive temperature to which they are subjected during the casting operation, such deformation being especially noticeable in a long mold such as is necessary for easting pipes, and consequently a metallic mold could not be used for continuous casting.

All of the disadvantages above referred to are eliminated by the use of metallic molds of the special construction forming the subject-matter of this application.

Referring to the drawings, the mold comprlses two half sections a and b respectively, which when brought together form a complete mold having a cylindrical inner wall, the diameter of the mold corresponding to the external diameter of the article which it is desired to'cast. The sections a and b of the mold are preferably provided with comparatively thin walls, for instance, for casting a pipe of 80 m. m. inner diameter and 4 metres in length, the thickness of the walls of the mold sections should be approX imately 20 m. m. By reason of this construction, any deformation of the mold due to high temperature is readily corrected by means of a comparatively slight exterior pressure or stress.

For supporting the mold during operation, I have provided a pair of base plates g and h respectively, shown in dotted lines in Fig. 1. Secured to the plate 9 are a plurality of guide blocks 0 and d, and carried by the plate h are a plurality of blocks 0' and cl, for retaining and guiding the sections of the mold in the manner hereinafter described. The guide blocks 0 and 0 are each provided with a longitudinal slot, preferably of dove-tail formed in cross-section, while the sections a and b have formed thereon a plurality of projections 6 also of dovetail form and adapted to slidably fit the slots in the guide members 0 and 0, as clearly shown in Fig. 4. The guide blocks cl and (Z are also each provided with a longitudinal slot, which, however, is prefera ly of rectangular form in cross-section, while the sections a and b are provided with projections f adapted to slidably fit said slots. The projections e and f of the mold sections are in axial alinement, and are connected by longitudinal ribs 70.

Each of the mold sections a and b is provided near one end thereof and beyond the outermost projection 6, with a projection m having longitudinally inclined or tapered sides, the larger ends of which are wider than the adjacent projections 6 so that the projections m will not pass through the slots in the guide members 0 and 0, whereby when the mold is assembled in vertical position as shown in Fig. 1 it will be prevented from sliding downwardly out of its guide members by the engagement of the shoulvided with a pair of curved-wings i adapted to embrace the mold section Z), the distance between the wings i beiln gsuchthat the longitudinal flanges of the mold sections snugly fit-therehetween, as shown in Fig. l, whereby the lateral displacement of the -mold sections relativelyto each other is prevented. provided with a pair of wedge-shaped lugs The mold sections are each further or projections ,7', "one at each side thereof, said lugs being disposed upon the longitudinal edges-ofthefianges of the meld sections, as shown in Fig. 3. The angle "and position of tl1e' lugsjare such that when the mold sections a and b are brought into cont-iguous relation ithe'lugs of one section will engage with and lie upon the lugs of the other section, as shown clearly .in Fig. 1, whereby the sections a' and b are maintained in correct longitudinal position relative to each other.

The operation'of theapparatus is as'follows: One of the base plates,'for instance, the plate 9, 'is'secured @to ca fixed support, such as a rigid vertical wall, while the other plate it may be mounted on the ram o f-a hydraulic press and is moved toward and from the mold "section a during the operation of'the press. When a'casting is to be made, the sections a and b :are first separated sufficientlyfa-r apart to permit a core which has been prepared-for thepur-pose, to be placed between said sections, whereupon the movable section b is moved by means of the ram or other apparatus into engagement with the section a. The core 10 herein shown comprises a metallic tube having a nu-mber'of perforations, said tube'being provided with a covering or casingof sand. The core, however, forms no part of the present invention,

and may be made'in any well-known manner. The ram or other operating mechanism is advanced suiiiciently to bring the longitudinal flanges of the section 6 into close contact with-those of the section a, so that the longitudinal flanges o'fboth sections will lie between the win 's i of the 'ui'de members 0 and (Z. Durin this operation, the wedgeshaped lugs j will have come into contact with each other and will act to-prevent any longitudinal displacement of one section relatively to the other. At the same time, the bottom fian es of the mold section and projections'o ,(s own in dotted lines at the upper end of Fig. 1) act to center the core at and retain it in proper positionduring the casting operation. The mold is then heated the mold is very small compared with the size of the pipe to be cast, and consequently the temperature ofgthe mold will quickly rise to a point near to that of the molten 'metal, so that very little heat will be absorbedby the mold. As soon as the cast pipe begins to contract the mold section Z) is backed-away from the section 01., whereby the cast pipe may be removed a-ndpermitted to freely contract. The mold, having been formed or distorted. Owing, however, to the fact that the wall is comparatively thin, the pressure necessary to again bring the mold section into contiguous relation will correct the deformation, such correction being aided bythe guiding elements hereinbefore described. While I have described and illustrated 'a mold divided into two sections, one being maintained in fixed position and the other movable toward and from the fixed section, it is obvious that for casting pipes of large diameter, the mold may be divided into three or more sections, one being fixed and the others movable toward and from said fixed section. It is, therefore,to be unport the other section for slidable movement longitudinally, a pair of wings carried by said movable guide blocks and adapted to engage said first section'thereby to prevent lateral displacement of the sections, and wedge-shaped projections carried by said sections and adaptedto be brought into cooperative engagement thereby to prevent longitudinal dlsplacement of the sections.

In testimony whereotI have signed my name to this specification.

'- eonsnnao KUBOlA.

heated by the molten metal to a high temperature, will probably be somewhat de- 

